Avoid spamming the management room with errors

The intervals are arbitrarily defined.

Fixes https://github.com/matrix-org/mjolnir/issues/10

src/ErrorCache.ts

@@ -0,0 +1,59 @@
+/*
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+export const ERROR_KIND_PERMISSION = "permission";
+export const ERROR_KIND_FATAL = "fatal";
+
+const TRIGGER_INTERVALS = {
+    [ERROR_KIND_PERMISSION]: 3 * 60 * 60 * 1000, // 3 hours
+    [ERROR_KIND_FATAL]: 15 * 60 * 1000, // 15 minutes
+};
+
+export default class ErrorCache {
+    private static roomsToErrors: { [roomId: string]: { [kind: string]: number } } = {};
+
+    private constructor() {
+    }
+
+    public static resetError(roomId: string, kind: string) {
+        if (!ErrorCache.roomsToErrors[roomId]) {
+            ErrorCache.roomsToErrors[roomId] = {};
+        }
+        ErrorCache.roomsToErrors[roomId][kind] = 0;
+    }
+
+    public static triggerError(roomId: string, kind: string): boolean {
+        if (!ErrorCache.roomsToErrors[roomId]) {
+            ErrorCache.roomsToErrors[roomId] = {};
+        }
+
+        const triggers = ErrorCache.roomsToErrors[roomId];
+        if (!triggers[kind]) {
+            triggers[kind] = 0;
+        }
+
+        const lastTriggerTime = triggers[kind];
+        const now = new Date().getTime();
+        const interval = TRIGGER_INTERVALS[kind];
+
+        if ((now - lastTriggerTime) >= interval) {
+            triggers[kind] = now;
+            return true;
+        } else {
+            return false;
+        }
+    }
+}

src/Mjolnir.ts

@@ -22,6 +22,7 @@ import { COMMAND_PREFIX, handleCommand } from "./commands/CommandHandler";
 import { applyUserBans } from "./actions/ApplyBan";
 import config from "./config";
 import { logMessage } from "./LogProxy";
+import ErrorCache, { ERROR_KIND_FATAL, ERROR_KIND_PERMISSION } from "./ErrorCache";
 
 export const STATE_NOT_STARTED = "not_started";
 export const STATE_CHECKING_PERMISSIONS = "checking_permissions";
@@ -166,13 +167,13 @@ export class Mjolnir {
         this.banLists = banLists;
     }
 
-    public async verifyPermissions(verbose = true) {
+    public async verifyPermissions(verbose = true, printRegardless = false) {
         const errors: RoomUpdateError[] = [];
         for (const roomId of Object.keys(this.protectedRooms)) {
             errors.push(...(await this.verifyPermissionsIn(roomId)));
         }
 
-        const hadErrors = await this.printActionResult(errors, "Permission errors in protected rooms:");
+        const hadErrors = await this.printActionResult(errors, "Permission errors in protected rooms:", printRegardless);
         if (!hadErrors && verbose) {
             const html = `<font color="#00cc00">All permissions look OK.</font>`;
             const text = "All permissions look OK.";
@@ -216,22 +217,42 @@ export class Mjolnir {
             // Wants: ban, kick, redact, m.room.server_acl
 
             if (userLevel < ban) {
-                errors.push({roomId, errorMessage: `Missing power level for bans: ${userLevel} < ${ban}`});
+                errors.push({
+                    roomId,
+                    errorMessage: `Missing power level for bans: ${userLevel} < ${ban}`,
+                    errorKind: ERROR_KIND_PERMISSION,
+                });
             }
             if (userLevel < kick) {
-                errors.push({roomId, errorMessage: `Missing power level for kicks: ${userLevel} < ${kick}`});
+                errors.push({
+                    roomId,
+                    errorMessage: `Missing power level for kicks: ${userLevel} < ${kick}`,
+                    errorKind: ERROR_KIND_PERMISSION,
+                });
             }
             if (userLevel < redact) {
-                errors.push({roomId, errorMessage: `Missing power level for redactions: ${userLevel} < ${redact}`});
+                errors.push({
+                    roomId,
+                    errorMessage: `Missing power level for redactions: ${userLevel} < ${redact}`,
+                    errorKind: ERROR_KIND_PERMISSION,
+                });
             }
             if (userLevel < aclLevel) {
-                errors.push({roomId, errorMessage: `Missing power level for server ACLs: ${userLevel} < ${aclLevel}`});
+                errors.push({
+                    roomId,
+                    errorMessage: `Missing power level for server ACLs: ${userLevel} < ${aclLevel}`,
+                    errorKind: ERROR_KIND_PERMISSION,
+                });
             }
 
             // Otherwise OK
         } catch (e) {
             LogService.error("Mjolnir", e);
-            errors.push({roomId, errorMessage: e.message || (e.body ? e.body.error : '<no message>')});
+            errors.push({
+                roomId,
+                errorMessage: e.message || (e.body ? e.body.error : '<no message>'),
+                errorKind: ERROR_KIND_FATAL,
+            });
         }
 
         return errors;
@@ -294,6 +315,7 @@ export class Mjolnir {
             if (event['sender'] === await this.client.getUserId()) return; // Ignore ourselves
             if (event['type'] === 'm.room.power_levels' && event['state_key'] === '') {
                 // power levels were updated - recheck permissions
+                ErrorCache.resetError(roomId, ERROR_KIND_PERMISSION);
                 const url = this.protectedRooms[roomId];
                 let html = `Power levels changed in <a href="${url}">${roomId}</a> - checking permissions...`;
                 let text = `Power levels changed in ${url} - checking permissions...`;
@@ -329,9 +351,17 @@ export class Mjolnir {
         }
     }
 
-    private async printActionResult(errors: RoomUpdateError[], title: string = null) {
+    private async printActionResult(errors: RoomUpdateError[], title: string = null, logAnyways = false) {
         if (errors.length <= 0) return false;
 
+        if (!logAnyways) {
+            errors = errors.filter(e => ErrorCache.triggerError(e.roomId, e.errorKind));
+            if (errors.length <= 0) {
+                LogService.warn("Mjolnir", "Multiple errors are happening, however they are muted. Please check the management room.");
+                return true;
+            }
+        }
+
         let html = "";
         let text = "";
 

src/actions/ApplyAcl.ts

@@ -21,6 +21,7 @@ import { Mjolnir } from "../Mjolnir";
 import config from "../config";
 import { LogLevel } from "matrix-bot-sdk";
 import { logMessage } from "../LogProxy";
+import { ERROR_KIND_FATAL, ERROR_KIND_PERMISSION } from "../ErrorCache";
 
 /**
  * Applies the server ACLs represented by the ban lists to the provided rooms, returning the
@@ -69,7 +70,9 @@ export async function applyServerAcls(lists: BanList[], roomIds: string[], mjoln
                 await logMessage(LogLevel.WARN, "ApplyAcl", `Tried to apply ACL in ${roomId} but Mjolnir is running in no-op mode`);
             }
         } catch (e) {
-            errors.push({roomId, errorMessage: e.message || (e.body ? e.body.error : '<no message>')});
+            const message = e.message || (e.body ? e.body.error : '<no message>');
+            const kind = message.includes("You don't have permission to post that to the room") ? ERROR_KIND_PERMISSION : ERROR_KIND_FATAL;
+            errors.push({roomId, errorMessage: message, errorKind: kind});
         }
     }
 

src/actions/ApplyBan.ts

@@ -20,6 +20,7 @@ import { Mjolnir } from "../Mjolnir";
 import config from "../config";
 import { logMessage } from "../LogProxy";
 import { LogLevel } from "matrix-bot-sdk";
+import { ERROR_KIND_FATAL, ERROR_KIND_PERMISSION } from "../ErrorCache";
 
 /**
  * Applies the member bans represented by the ban lists to the provided rooms, returning the
@@ -80,7 +81,12 @@ export async function applyUserBans(lists: BanList[], roomIds: string[], mjolnir
                 }
             }
         } catch (e) {
-            errors.push({roomId, errorMessage: e.message || (e.body ? e.body.error : '<no message>')});
+            const message = e.message || (e.body ? e.body.error : '<no message>');
+            errors.push({
+                roomId,
+                errorMessage: message,
+                errorKind: message.includes("You don't have permission to ban") ? ERROR_KIND_PERMISSION : ERROR_KIND_FATAL,
+            });
         }
     }
 

src/commands/PermissionCheckCommand.ts

@@ -18,5 +18,5 @@ import { Mjolnir } from "../Mjolnir";
 
 // !mjolnir verify
 export async function execPermissionCheckCommand(roomId: string, event: any, mjolnir: Mjolnir) {
-    return mjolnir.verifyPermissions();
+    return mjolnir.verifyPermissions(true, true);
 }

src/models/RoomUpdateError.ts

@@ -17,4 +17,5 @@ limitations under the License.
 export interface RoomUpdateError {
     roomId: string;
     errorMessage: string;
+    errorKind: string;
 }